The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Brazing tools are in particular applied in the field of aeronautics, and more particularly for manufacturing revolution parts, or having two complex surfaces, for example closed surfaces, in particular revolution surfaces, to be put opposite to each other, such as gas ejection cones for aircraft turbojet engine or IFS (Internal Fixed Structure).
In a known manner, the brazing is a technique for the assembly of two materials.
There is known the brazing method carried out using a filling metal of a different nature having a melting temperature lower than the melting temperature of the materials to be assembled and capable of properly wetting the surfaces of said materials. In practice, the brazing is carried out by interposition of the filling metal between the two components to be assembled, the area to be brazed being then heated at a temperature allowing the melting of the filling metal but not the melting of the components to be assembled. The liquefied filling metal wets the surfaces of the two components to be assembled and is then cooled so as to solidify between the two components in order to ensure the link therebetween.
The filling metal is generally tin, copper, silver, aluminum, nickel or else precious metal alloys.
It is also known from the prior art a brazing tooling using a gas pressure. Such a device comprises a cylindrical central barrel constituting gas chamber, contained in a counter-shape on which a sealing device consisting of upper and lower flanges is fastened by screwing. The pressure is applied on an inner cylindrical skin, causing the plating of said skin on a honeycomb structure, then of the assembly consisting of the inner skin and the honeycomb on an outer skin. Then, the cylindrical assembly inner skin/honeycomb structure/outer skin is deformed under the effect of the pressure until meeting the counter-shape whose inner surface takes the desired final shape.
Such devices have disadvantages in particular in that the use of a metal brazing tooling involves an additional cost of the thermal cycle related to the inertia of the tooling and to the inertia of the metal to be brazed; the use of a brazing tooling by gas pressure has in particular the disadvantage that it involves an additional cost to carry out the gas sealing, as well as technical difficulties such as the control of the pressure, time and temperature parameters, in order to avoid a crushing of the honeycomb and to optimize the marking phenomenon of the honeycomb (telegraphing) on the skin.
On the other hand, the brazing techniques of the prior art for large-sized parts have the disadvantage of a significant temperature gradient during the heating of the parts to be brazed, which in particular extends the thermal cycle time and involves an additional cost due to the fact that the desired temperatures for the brazing must be greater.